JPH0766142B2 - Memory backup device for camera - Google Patents

Description

The present invention relates to a memory backup device for a camera.

[Conventional technology]

At present, in a compact camera, the shooting mode such as film winding and rewinding, and the storage of data such as the number of shots are performed by a microcomputer and a RAM accessed by the microcomputer. That is, the microcomputer provided on the body side of the camera performs each processing according to the shooting sequence program written in the ROM, and the progress thereof is temporarily stored in the RAM and is rewritten to perform the sequence. Will continue. In such a camera, the power supply battery for driving the shutter and the film feeding motor is shared by the microcomputer and the battery for storing data on the RAM. At the time of replacement, the data in the RAM will be lost the moment the battery is removed.

[Problems to be solved by the invention]

However, in the camera as described above, the battery replacement is not always performed after the use of the camera is completely completed. In other words, it is not uncommon for the battery to be replaced during continuous shooting or during rewinding of the film. When the battery is replaced at such a timing, the battery is once removed, so that the execution of the photographing sequence by the microcomputer is interrupted and the data on the RAM is also erased. Therefore, as a result of the loss of information about the number of shots up to which the shots have been taken during shooting, it becomes impossible to properly count the number of films after a new battery is loaded.
Also, during film rewinding after shooting,
Usually, each circuit unit is reset to the initial state by removing the battery, so it may not be possible to resume film rewinding after a new battery is loaded. Absent.

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and even if the battery is replaced at any time during the use of the camera, the processing after the interruption is performed after the battery is replaced. An object of the present invention is to provide a memory backup device for a camera that can be surely continued.

[Means for solving problems]

In order to achieve the above object, the present invention focuses on the fact that in many recent cameras, the main capacitor in the flash circuit is always rechargeable, and when the power battery is removed, the battery is replaced during battery replacement. , Controlling the charge stored in the capacitor and using it as a substitute for the power supply battery,
It was intended to be used to hold data on RAM.
That is, a voltage of a predetermined level is taken out from the already charged main capacitor by the voltage extracting means to stabilize it, and the stabilized voltage is supplied to the microcomputer and RAM immediately before the power supply from the power supply battery is interrupted, It's about backing up memory.

[Action]

According to the above configuration, the power battery of the camera is removed,
When the exchange is about to take place, the voltage obtained by the voltage extraction means described above temporarily replaces it and the RAM
And the microcomputer accessing it is powered. Therefore, no matter what timing the battery may be replaced after the main capacitor is charged, the data of various operations stored in the RAM will be saved, and when the operation is restarted, the processing before the battery replacement will be ensured. Will be able to continue.

〔Example〕

FIG. 1 is a view of a main body 1 of a compact camera using the present invention as seen from a diagonally lower side of a back surface. A shutter button 6 is provided on the right side of the upper part of the camera, a viewfinder 8 is provided at the center of the upper part of the back, a film counter display window 40 is provided on the right side of the viewfinder, and a film rewind button 7 is provided on the bottom of the main body. On the back surface of the main body 1, there is provided a back lid 2 which is openably and closably attached. On the bottom surface of the main body 1, for example, a single-sided battery lid 3 that is opened and closed when the AA dry battery 5 is replaced is provided. It is possible to open 3 and replace the dry battery 5 placed in the battery chamber 10.

FIG. 2 is a sectional view showing the structure of the opening / closing part of the battery lid 3 shown in FIG. The battery lid 3 is opened and closed by sliding the knob 4. That is, the battery lid 3 in the closed position shown by the broken line can be opened and closed by moving the knob 4 to the right with respect to the spring 38. A switch 9 faces the moving path of the knob 4, and when the battery lid 3 is in the closed position, OF
In the F state, and when the battery lid 3 is opened, it becomes the ON state.

FIG. 3 shows a simplified electric circuit diagram of the strobe device 13 and a block diagram of an electric circuit portion 12 centered on the controller 11 for controlling various main functions of the camera.

In FIG. 3, the controller 11 built in the main body is
The shooting mechanism of the camera built in the main body 1, that is, the autofocus device 14, the shutter device 15, the film feeding device 16, the number counter 17 for counting the number of photographic films, and the strobe device 13 are controlled. These are powered by the dry battery 5 loaded in the main body 1.

A program ROM 18 is connected to the controller 11. A sequence program for operating the camera is stored in this program ROM 18, and the controller 11
This sequence program is accessed by, for example, the sequence processing in the photographing mode and the sequence processing in the rewind mode are executed. When these sequence processes are performed, data indicating how many processes have been executed for each operation of each mechanical unit processed as a subroutine, that is, the autofocus device 14, the shutter device 15, etc. is used for sequence program monitoring. RAM 2
It is written to 0 sequentially. In addition, the number counter 17
A count-up signal is output every time the shutter device 15 is operated, and the count value is displayed on the film counter display window 40.
(Fig. 1).

In addition, the controller 11 sends the DC-DC
It also controls the operation of the converter 22. That is, the controller 11 automatically charges the main capacitor 24 by a timing signal such as the completion of the operation of the film feeding device or when it is detected that the charging voltage level of the main capacitor 24 becomes a predetermined value or less. Let it start.

The operation of the above configuration is performed as follows.
First, when the loading of the film cartridge is detected when the back cover 20 is closed, the controller 11 causes the program ROM 1
8 is accessed and the sequence program is started in the normal shooting mode. Then, first, the film feeding device 16 is operated to feed the film in the air, and the preparation for photographing is completed.

When the shutter button 6 is pressed to the first step, the controller 11 gives an operation command signal to the autofocus device 14 in response to a signal from the release signal generation circuit 36, whereby the autofocus device 14 operates and focus adjustment is performed.
When this focus adjustment is completed, the second-step pressing of the shutter button 6 is completed, and the shutter device 15 is operated by the second-step pressing to take an image. When it is detected by a known photometric circuit (not shown) that the subject brightness is below a predetermined level, the synchro switch 39 is turned on in synchronization with the operation of the shutter, and the trigger circuit 26 stores it in the main capacitor 24. Charge is a flash discharge tube
Discharged at 25. When the shutter operation is completed, the film feeding device 16 operates to wind the film by one frame, and the number of sheets counter 17 is incremented by "1". After that, the photographing can be continued in the same manner.

While the normal shooting mode described above is being carried out, in addition to being set to the shooting mode at the present moment, the autofocus device 14, the shutter device 15, the film feeding device.
The process in which routines such as 16, the number of sheets counter 17, the strobe device 13 and the like are exhausted are written in the RAM 20 as binary data.

On the other hand, when the shooting of all the frames of the film loaded in the camera is completed, the sequence program in the shooting mode ends, and the rewind standby state is set. When the rewind button 7 is pressed from this state, a start signal is supplied from the rewind signal generation circuit 37 to the controller 11, whereby the processing in the rewind mode stored in the program ROM 18 is started, and the film feeding apparatus is started. 16 operates to rewind the film to the cartridge side. Even when this rewind mode is activated, the RAM 20 is set to the rewind mode as in the above-described shooting mode, the film feeding device 16 is operating for rewinding, or Data such as completion of rewinding is sequentially written.

By the way, if the dry battery 5 is consumed during the normal operation such as the photographing mode and the rewind mode, and the battery cover 3 is opened for replacement or for another reason,
As shown in FIG. 2, the switch 9 is turned on from the off state.
Changes to the state of. As a result, the charging voltage of the main capacitor 24 is applied to the voltage extracting circuit of FIG. 3, that is, the resistors 28 and 29. At this time, the main capacitor 24 has 280
DC voltage of about 350V is charged, but resistor 2
The voltage is divided by 8,29. Then, by setting the resistance value of the resistor 28 to be much larger than that of the resistor 29, the voltage applied across the resistor 29 is dropped to a level of several V, which is suitable for supplying power to the controller 11 and the RAM 20.
This voltage is transmitted to the controller 11 through the diode 32 that limits the reverse flow of current as a stable power source without voltage fluctuation by passing through the regulator circuit 30.

Just before opening the battery cover 3 like this,
If 24 is used as an auxiliary power source for the controller 11, the data on the RAM 20 and the count value of the number counter 17 will not disappear even if the dry battery 5 is removed thereafter. As a result, when a new dry battery 5 is inserted and the battery lid 3 is closed, the controller 11 restarts the sequence program based on the data before opening the battery lid 3, so the main capacitor
If the 24 is charged, even film 1 after shooting
Even if the dry battery 5 is replaced during the frame feeding, the operation is restarted from the film feeding one frame. When the dry battery 5 is replaced in the middle of the rewind mode, the rewinding of the film is started after the new dry battery 5 is connected.

〔The invention's effect〕

As described above, according to the present invention, the backup of the memory is performed by using the main capacitor of the constantly charging strobe device. Therefore, after the main capacitor is charged, even if the power battery is removed from the camera for battery replacement, it is necessary to continue the camera sequence program such as the identification data of the shooting mode and rewind mode and the number of film shots. Since the data can be saved, the sequence program after the interruption can be continued and restarted after the battery is replaced.

[Brief description of drawings]

FIG. 1 is a perspective view of a camera body using the present invention. FIG. 2 is a sectional view showing a state where the battery cover of the camera is opened. FIG. 3 is a block diagram showing an embodiment of the present invention. 3 …… Battery lid 5 …… Batteries 9 …… Switch 12 …… Main unit electric circuit 13 …… Strobe circuit 24 …… Main capacitor 40 …… Film counter display window

Claims (1)

[Claims] 1. A camera provided with a constant charge type strobe, which is operated by power supply from a power supply battery and a control circuit built in the camera to control the operation sequence of the camera. Strobe circuit, a memory that is accessed by the control circuit and sequentially stores the progress of the camera operation sequence, a voltage extracting means that extracts the voltage from the main capacitor in the strobe circuit, and a means that stabilizes the extracted voltage. And a means for detecting the removal of the power battery, the voltage obtained by the voltage extracting means is temporarily supplied to the control circuit by a signal from the detecting means, and the data stored in the memory is stored. A memory backup device for a camera that retains data.